Photographic products and processes with silver complexes as antifoggants

ABSTRACT

Compounds represented by the formula Ag(L) 2 2X , wherein L is a macrocyclic ligand and X is an anion, are used for the prevention of fog in photographic products and processes, particularly diffusion transfer products and processes.

United States Patent [1 1 Charkoudian [451 May 13, 1975 PHOTOGRAPHICPRODUCTS AND PROCESSES WITH SILVER COMPLEXES AS ANTIFOGGANTS John C.Charkoudian, Cambridge,

Inventor:

- Mass.

Assignee: Polaroid Corporation, Cambridge,

Mass.

Filed: June 15, 1973 Appl. No.: 370,220

US. Cl 96/3; 96/29 R; 96/29 D; 96/74; 96/76 R; 96/77; 96/99; 96/100;96/107; 96/110; 96/120 Int. Cl. G03c 7/00; G03c 5/54; G030 1/76;

G03c 3/00; G030 1/48; G030 1/40; G03c 1/10; G03c 1/28; G03c 1/30; G03c1/02; G030 1/08 Field of Search 96/3, 29 D, 29 R, 76 R,

[56] References Cited UNITED STATES PATENTS 3,178,285 4/1965 Anderau etal. 96/99 3,552,968 1/1971 Willems 96/76 R 3,615,428 10/1971 Weed 96/29R 3,647,437 3/1972 Land 96/3 Primary Examiner Ronald H. Smith AssistantExaminer-Richard L. Schilling Attorney, Agent, or Firm-Robert M. Ford;Philip G. Kiely 28 Claims, No Drawings PHOTOGRAPHIC PRODUCTS ANDPROCESSES WITH SILVER COMPLEXES AS ANTIFOGGANTS The present inventionrelates to photography and more particularly to photographic productsand processes.

It has been extensively reported in literature pertaining to photographythat photosensitive silver halide emulsions, and particularlyphotosensitive gelatinosilver halide emulsions, have a tendency to losesensitivity and to become spontaneously developable without exposure tolight. This phenomenon, characterized as chemical fog, may be defined asthe density above base level that is developed in emulsion areas thathave received no intentional exposure and, in general, is not uniformlydistributed over a selectively photoexposed emulsion, being greatest inthe unexposed areas and decreasing with increased exposure in anon-linear manner.

In both silver and color photographic systems, the latter where silverhalides are used to control image dye formation, fog results in a lossof image acuity.

Chemical fog may be divided into two classes: inher' ent fog, that is,fog which is emulsion initiated; and induced fog, that is, fog which isinitiated during development. Induced fog appears to be due to physicaldevelopmentabout extra-granular centers and inherent fog is probablydueto the presence of grains bearing a catalytic site sensitivity speckwhich is unavoidably introduced and which is equivalent in itsproperties to latent image. Induced fog accordingly may be unaffected bythe level of inherent fog. Thus it will be readily appreciated that anemulsion susceptible to the development of chemical fog requires silverhalide grains possessing a catalytic center of sufficient size to bespontaneously developable and/or grains unprotected fromnondiscriminatory development.

Various and sundry procedures and additives have been disclosed in theart to provide an increase in the stability of photosensitive silverhalide emulsions by reducing the tendency of photosensitive compositionsto fog. These procedures usually increase the speed-to-fog ratio;otherwise there would be no point in using them unless the requirementfor a low fog level completely are free of fogging contaminants andwhich have desirable ratios of restrainer to sensitizer; reduce thelevel of chemical sensitization; and add inorganic or organic fogretarding adjuncts.

This invention relates primarily to the latter item above, and moreparticularly, to the use of a specified class of antifoggants.

Various diffusion transfer systems for forming color images haveheretofore been disclosed in the art. Generally speaking, such systemsrely for color image formation upon a differential in mobility orsolubility of a dye image-providing material obtained as a function ofdevelopment so as to provide an imagewise distribution of such materialwhich is more diffusible and which is therefore selectively transferred,at least in part, by diffusion, to a superposed dyeable stratum toimpart thereto the desired color transfer image. The differential inmobility orsolubility may for example be obin the processing compositionbut which are selectively rendered diffusible in an imagewise pattern asa function of development. These materials may be complete dyes or dyeintermediates, e.g., color couplers.

As examples of initially soluble or diffusible materials and theirapplication in color diffusion transfer, mention may be made of thosedisclosed, for example, in US. Pat. Nos. 2,647,049; 2,661,293;2,698,244; 2,698,798; 2,802,735; 2,774,668; and 2,983,606. As

examples of initially non-diffusible materials and their use in colortransfer systems, mention may be made of the materials and systemsdisclosed in US. Pat. Nos. 3,443,939; 3,443,940; 3,227,550; 3,227,551;3,227,552; 3,227,554; 3,243,294 and 3,445,228.

In any of these systems, multicolor images are obtained by employing afilm unit containing at least two selectively sensitized silver halidelayers each having associated therewith a dye image-providing materialexhibiting desired spectral absorption characteristics. The mostcommonly employed elements of this type are the so-called tripackstructures employing a blue-, a green, and a red-sensitive silver halidelayer having associated therewith, respectively, a yellow, 2 magenta anda cyan dye image-providing material.

A particularly useful system for forming color images by diffusiontransfer is that described in US. Pat. No. 2,983,606, employing dyedevelopers (dyes which are also silver halide developing agents) as thedye imageproviding materials. In such systems, a photosensitive elementcomprising at least one siliver halide layer having a dye developerassociated therewith (in the same or in an adjacent layer) is developedby applying an aqueous alkaline processing composition. Exposed anddevelopable silver halide is developed by the dye developer which inturn becomes oxidized to provide an oxidation product which isappreciably less diffusible than the unreacted dye developer, therebyproviding an imagewise distribution of diffusible dye developer in termsof unexposed areas of the silver halide layer, which imagewisedistribution is then transferred, at least in part, by diffusion, to adyeable stratum to impart thereto a positive dye transfer image.Multicolor images may be obtained with a photosensitive element havingtwo or more selectively sensitized silver halide layers and associateddye developers, a tripack structure of the type described above and invarious patents including the aforementioned US. Pat. No. 2,983,606being especially suitable for accurate color recordation of the originalsubject matter.

In color diffusion transfer systems of the foregoing description, colorimages are obtained by exposing a photosensitive element or negativecomponent comprising at least a light-sensitive layer, e.g., a gelatinosilver halide emulsion layer, having a dye imageproviding materialassociated therewith in the same or in an adjacent layer, to form adevelopable image; developing this exposed element with a processingcomposition to form an imagewise distribution of a soluble anddiffusible image-providing material; and transfertive-positive filmunits wherein the negative and positive components are laminated and/orotherwise physically retained together at least prior to imageformation.

While the present invention is applicable both to those systems whereinthe dyeable stratum is contained on a separate element and to thosesystems wherein the dyeable stratum and the photosensitive stratacomprise a unitary structure, of particular interest are those integralnegative-positive film units adapted for forming color transfer imagesviewable without separation, i.e., wherein the positive component neednot be separated from the negative component for viewing purposes.Generally, such film units comprise a plurality of essential layersincluding a negative component comprising at least one light-sensitivesilver halide and associated dye image-providing material and a positivecomponent comprising dyeable stratum. These components may be laminatedtogether or otherwise secured together in physical juxtaposition as asingle structure. Film units intended to provide multicolor imagescomprise two or more selectively sensitized silver halide layers eachhaving associated therewith an appropriate dye image-providing materialexhibiting desired spectral absorption characteristics. As washeretofore mentioned the most commonly employed negative components forforming multicolor images are of the tripack structure containing ablue-, a greenand a redsensitive silver halide layer having associatedtherewith 'in the same or in a contiguous layer a yellow, a magenta anda cyan dye image-providing material respectively. Interlayers or spacerlayers may if desired be provided between the respective silver halidelayers and associated dye image-providing materials. In addition to theaforementioned essential layers, such film units further include meansfor providing a reflecting layer between the dyeable stratum and thenegative component in order to mask effectively the silver image orimages formed as a function of development of the silver halide layer orlayers and any remaining associated dye image-providing material and toprovide a background for viewing the color image formed in the dyeablestratum, without separation, by reflected light. This reflecting layermay comprise a preformed layer of a reflecting agent included in theessential layers of the film unit or the reflecting agent may beprovided after photoexposure, e.g., by including the reflecting agent inthe processing composition. These essential layers are preferablycontained on a transparent dimensionally stable layer or support memberpositioned closest to the dyeof the essential layers so that theaforementioned essential layers are sandwiched or confined between apair of dimensionally stable layers or support members, at least one ofwhich is transparent to permit viewing therethrough of a color transferimage obtained as a function of development of the exposed film unit inaccordance with the known color'diffusion transfer system such as willbe detailed hereinafter. In a particularly preferred form such filmunits are employed in conjunction with a rupturable container of knowndescription containing the requisite processing composition and adaptedupon application of pressure of applying its contents to develop theexposed film unit, e.g., by applying the processing composition in asubstantially uniform layer between the dyeable stratum and the negativecomponent. It will be appreciated that the film unit may optionallycontain other layers performing specific desired functions, e.g., spacerlayers, etc.

Opacifying means may be provided on either side of the negativecomponent so that the film unit may be processed in the light to providethe desired color transfer image. In a particularly useful embodimentsuch opacifying means comprise an opaque dimensionally stable layer orsupport member positioned on the free or outer surface of the negativecomponent, i.e., on the surface of the film unit opposed from thepositive component containing the dyeable stratum to preventphoto-exposure by actinic light incident thereon from this side of thefilm unit and an opacifying agent applied during development between thedyeable stratum and the negative component, e.g., by including theopacifying agent in a developing composition so applied, in order toprevent further exposure (fogging) by actinic light incident thereonfrom the other side of the film unit when the thus exposed film unit isdeveloped in the light. The last-mentioned opacifying agent may comprisethe aforementioned reflecting agent which masks the negative componentand provides the requisite background for viewing the transfer imageformed thereover. Where this reflecting agent does not by itself providethe requisite opacity it may be employed in combination with anadditional opacifying agent in order to prevent further exposure of thelight-sensitive silver halide layer or layers by actinic light incidentthereon.

As examples of such integral negative-positive film units for preparingcolor transfer images viewable without separation as reflection prints,mention may be made of those described and claimed in US. Pat. Nos.

3,415,644; 3,415,645; 3,415,646; 3,473,925; 3,573,043; 3,576,625;3,573,042; 3,594,164; and 3,594,165.

In general, the integral negative-positive film units of the foregoingdescription, e.g., those described in the aforementioned patents,areexposed to form a devel- 'opable image and thereafter developed byapplying the appropriate processing composition to develop exposedsilver halide and to form, as a function of development, an imagewisedistribution of diffusible dye image-providing material which istransferred, at least in part by diffusion, to the dyeable stratum toimpart thereto the desired color transfer image, e.g., a positive colortransfer image. Common to all of these systems included in the essentiallayers of the laminar structure comprising the film unit, and in othersit is provided at some time thereafter, e.g., by including a suitablelightreflecting agent, for example, a white pigment such as titaniumdioxide, in the processing composition which is applied between thedyeable stratum and the next adjacent layer to develop the latent imageand to form the color transfer image.

A preferred opacification system to be contained in the processingcomposition is that described in the copending application of Edwin H.Land, Ser. No. 43,782, filed June 5, 1970 and U.S. Pat. No. 3,647,437issued Mar. 7, 1972, which are incorporated herein by reference in theirentirety.

In lieu of having the reflecting pigment contained in the processingcomposition, the reflecting pigment needed to mask the photosensitivestrata and to provide the requisite background for viewing the colortransfer image formed in the receiving layer may be contained initiallyin whole or in part as a preformed layer in the film unit, as thatdisclosed in the US. Pats. of Edwin H. Land, Nos. 3,615,421 issued Oct.26, 1972 and 3,620,724 issued Nov. 16, 1971. The reflecting pigment maybe generated in situ as is disclosed in the US. Pats. of Edwin. H. Land,Nos. 3,647,434 and 3,647,435, both issued Mar. 7, 1972.

In the various color diffusion transfer systems which have previouslybeen described and which employ an aqueous alkaline processing fluid, itis well known to employ an acid-containing layer to lower theenvironmental pH following substantial dye transfer in order to increasethe image stability and/or to adjust the pH from a first pH at which theimaging dyes are diffusible to a second (lower) pH at which they arenot. For example, U.S. Pat. No. 3,362,819 discloses systems wherein thedesired pH reduction may be effected by providing a polymeric acid layeradjacent the dyeable stratum. As examples of other useful neutralizinglayers, in addition to those disclosed in the aforementioned U.S. Pat.No. 3,362,819, mention may be made of those disclosed in the followingcopending applications: Ser. No. 165,171 of Schlein et al., filed July22, 1971; Ser. No. 214,746 of Bedell, filed Jan. 3, 1972; Ser. No.208,616 of Taylor, filed Dec. 16, 1971; Ser. No. 231,835 (Case No. 4526)of Sahatjian et al., filed Mar. 6, 1972, etc.

An inert interlayer or spacer layer may be and is preferably disposedbetween the polymeric acid layer and the dyeable stratum in order tocontrol the pH reduction so that it is not premature and henceinterferes with the development process, e.g., to time control the pHreduction. Suitable spacer or timer layers for this purpose aredescribed with particularity in US. Pat. No. 3,362,819 and in others,including US. Pat. Nos. 3,419,389; 3,421,893; 3,433,633; 3,455,686; and3,575,701.

While the acid layer and associated spacer layer are preferablycontained in the receiving element employed in systems wherein thedyeable stratum and photosensitive strata are contained on separateelements, e.g., between the support for the receiving element and thedyeable stratum; or associated with the dyeable stratum in thoseintegral film units, e.g., on the side of the dyeable stratum opposedfrom the negative component, they may, if desired, be associated withthephotosensitive strata, as is disclosed, for example, in US. Pat. Nos.3,362,821 and 3,573,043. In film units such as those described in theaforementioned US. Pat. Nos. 3,594,164 and 3,594,165, they also may becontained on the spreader sheet employed to facilitate application ofthe processing fluid.

Copending application Ser. No. 327,797, filed Jan. 29, 1973, nowabandoned and replaced by continuation-in-part application Ser. No.475,778, filed June 3, 1974, discloses the disproportionation of Ag inthe vicinity of the latent image by associating the silver halideemulsion layer with a macrocyclic ligand which is described in detail inthe indicated application and which will be described below. It isbelieved that the re action proceeds as follows:

2Ag L' H2O AgL Ag wherein L is the ligand. Disposal of the ligand L inthe emulsion acts as a sensitization or latensification agent.

. By employing compounds containing the described be.

ligands superior antifoggant properties can achieved.

SUMMARY OF THE INVENTION A compound which is water-soluble ,and stablein aqueous medium represented by the formula:

A L 2x wherein L is a macrocyclic ligand and X is an anion; has beenfound to provide superior antifoggant activity when disposed in a silverhalide emulsion.

DETAILED DESCRIPTION OF THE INVENTION It has now been found thatsuperior antifoggant properties have been achieved by disposing in asilver halide emulsion a water-soluble Ag salt of the formula:

A L 2xwherein L is a macrocyclic ligand and X is an anion. While not"intending to be bound by theory, it is be lieved that thewater-soluble, stable Ag salts react with bromine ions in the vicinityof the grain precipitating on the grain according to the followingequation:

wherein each Y comprises the atoms linking the respective nitrogen atomsand which, together with the respective nitrogen atoms, constitute thering system.

Preferably, the ligand comprises saturated and unsaturated macrocyclicSchiff base amines.

As examples of suitable ligands, mention may be made of the following: I

3 2\C C/ 3 H H H2 C N N C l0 an c H D HZC 2 C c H C I I H2 C (i}\H \HN--CH 2 2 CH3 C 3 2 H C-N n -cn i ii i H 2 C 2O CH (.2

CH c 3 H C C-(CH l l) H CN NCH H E. i

H C-N ncn H c ca I i\H 3 2 -7 3 2 CH --C c CH c 3 I H C N NCH 2 B- H I NN I -CH 2 2 40 5,5,7,l2,14,14hexamethy11,'4,8,ll-tetra- (c cazacyclotetradecane (tet b) I'he preparation of such ligands is known tothe art. See, for example, J.A.C.s.

5, 5, 7 12, 12, l4-hexamethyl-1,4,8, 11-tetra azacyclotetradecane Thepreparation of such ligands is known to the art.

See, for example, J.A.C.S. 2644 (1964).

The anion designated X may constitute any inorganic or organic anionimparting water-solubility to the salt and which is photographicallyinnocuous when dis- 2 posed in the emulsion. As examples of suitableanions, mention may be made of N0 C10 /2 S0 Br and CH CO The Ag salt isdisposed in the silver halide emulsion H and is generally employed at alevel of about 0.20

mgs./ft. to 0.50 mgs./ft.

2 The following nonlimiting examples illustrate the i novel emulsions ofthe present invention. The Controls H2c N -CH indicated in each Examplediffered from the invention H only in the absence of the silver salt.

c c EXAMPLE 1 A film unit was prepared by coating a polyester supportwith 50 mgs./ft. of magenta dye developer of the 2 formula:

HO-CH -CH N-SO HO-CH CH in about 150 mgslft. of gelatin. Over theabovedescribed layer was coated a blue-sensitized silver iodobromideemulsion containing 0.32 mgs./ft. ofAg(- teta) 2NO at a coverage ofabout 80 mgs./ft. of silver and about 80 mgs./ft. of gelatin. Over theemulsion layer was coated a layer of gelatin at a coverage of about 30mgs./ft. containing about 8 mgs./ft. of 4'-methylphenylhydroquinone. Thethus-formed negative was exposed through a step wedge to selectivelyfiltered radiation and then processed by contacting the negative with aprocessing composition while in superposition with an image-receivingelement in the dark for 10 minutes. The image-receiving elementcomprised a 4 mil polyethylene terephthalate film base having coatedthereon the following layers:

1. the partial butyl ester of polyethylene/maleic anhydride copolymerprepared by refluxing, for 14 hours, 300 grams of high viscositypoly-(ethylene/maleic anhydride), 140 grams of n-butyl alcohol and 1 cc.of 85 percent phosphoric acid to provide a polymeric acid layerapproximately 0.75 mil thick;

2. a 10 percent aqueous emulsion of a diacetone acrylamide/acrylamidecopolymer grafted onto a poly vinyl alcohol backbone to provide an inertspacer layer approximately 0.3 mil thick; and

3. A 2:1 mixture, by weight, of polyvinyl alcohol andpoly-4-vinylpyridine, at a coverage of approximately 600 mgs/ftf", toprovide a polymeric image-receiving layer approximately 0.40 mil thick.The processing 9999?? (A Jib) U D Control D Test The significantincrease in positive D is evidence of the suppression of fog in theemulsion of the present invention.

EXAMPLE II A film unit was prepared by coating a polyester support with50 mgs./ft. of yellow dye developer of the formula:

EXAMPLE III A film unit was prepared by coatingv a polyester supportwith 50 mgs./ft. of cyan dye developer of the formula:

in about 75 mgs./ft. of gelatin. Over the abovedescribed layer wascoated a red-sensitized silver iodobromide emulsion containing 0.32mgs./ft. of Ag(- teta)* 2NO at a coverage of about 80 mgs./ft. of silverand about 80 mgs./ft. of gelatin. Over the emulsion layer was coatedalayer of gelatin at a coverage of about 30 mgs./ft. The thus-formednegative was exposed and processed as in Example 1 above.

D Control 1.85 mu: Test EXAMPLE IV A film unit was prepared by coating apolyester support with 50 mgs./ft. of cyan dye developer of the formula:

' formula:

teta) 2NO' at a coverage of about 80 mgs./ft. of silver and about 80mgs./ft. of gelatin. Over the emulsion laye'r was coateda layer ofgelatin at a coverage of about 3Q mgs/f t. containingabout 8 rugs/ft? ofe 4'wmethylphenylhydroquinone. The thus-formed negative'was exposed andprocessed as in Example 1 above.

D5,, Control D Test.

EXAMPLE v A film unit was prepared by coating a polyester support with50 mgs./ft.

"in'yabbur 75 mg s./ ft. ,.of gelatin. Over the above'-- I describedlayer was'coated a'red-sensitized silver iodo- ',,bromide, emulsioncontaining 0.32 mgs./ft. of Ag(- sion's-of the present invention aresuitable'for use in photographic Systems employing other dyeimageforming materials as described in the above-mentioned patents andapplications. The silver halide emulsions of the present invention alsofind particular utility in black and white photographic processes and,particularly, in panchromatically sensitized silver halide emulsionsemployed in additive color photography.

EXAMPLE Vl I A film unit was prepared by coating a polyester supportwith 150 mgsjft} of 'a blue-sensitive silver iodobromide emulsioncontaining 6 mg./g. of silver of Ag(- teta) 200,. The emulsion layer wasovercoated with 30 mgs./ft. of gelatin. The thus-formed negative wasexposed according to the procedure of Example I. The processingcomposition and image-receiving element employed were from a PolaroidType 107 film unit (Poof a magenta dye developer of the laroidCorporation, Cambridge, Massachusetts). The thus-formed negative, ascompared with a film unit prei 015 V W 0 Q n in about 75 mgs/ft. ofgelatin. Over the abovedescribed layer was coated a green-sensitizedsilver iodobromide emulsion containing 0.32 mgsj ft. of Ag(- teta) 2N0;at a coverage of about 80 mgs./ft. of silver and about 80 mgs./ft. ofgelatin. Over the emulsion was coated a layer of gelatin at a coverageof about Inga/ft}. The thus-formed negative was exposed and processed asin Example 1 above except thatthe processing composition additionallycontained 0.2 percent of 4-methylphenylhydroquinone.

D Control D Test By employing the novel silver halideemulsions of thepresent invention, it will be noted that less fog is pro- -ducedthanwith similar emulsions which do not contain the novel antifoggant of thepresent invention.

While. the invention has been defined primarily with regard tophotographic systems employing dye develsilver halide emulopers, itshould be understood the pared and processed above, except that itcontained no silver salt, showed the following positive silver density:

D,,,,,, Control D Test In all of the above experiments the D,,,,-,, wassubstantially the same for the control and test negatives.

A preferred .film unit employs an image-receiving component intermediatethe photosensitive silver halide stratum and the additive multicolorscreen. In such a film unit, exposure of the silver halide emulsion isaccomplished through the screen unit and the imagereceiving component.Subsequent processing results in the formation of a positive silverimage in the imagereceiving component next adjacent the additivemulticolor-screen. The aforementioned film unit is one example of astructure which obviates registration problerns since the screenemployed for exposing is in automatic registration with the positivesilver image for viewing. In the aforementioned film unit, the silverhalide stratum may be removed or allowed to remain in positionsubsequent to formation of the positive silver image.

As examples of suitable film structures which comprise negative andpositive images in superposition and formed by diffusion transferreversal processes, mention may be made of US. Pat. Nos. 2,861,885;

2,726,154; 2,944,894; 3,536,488; and also US. Pat.

ploying as the image-receiving element a layer which provides anunusually effective silver precipitating environment which causes thesilver deposited therein to possess an extraordinarily high coveringpower in comparison with negative silver developed in the silver halidelayer. For greater discussion of such a phenomena, see Edwin H. Land,One Step Photography, Photographic Journal, Section A, pages 7 to 15,January, 1950. t

The above-mentioned integral film unit applications are particularlydesirable for employment as cine film for motion picture projection, forexample, such as the cine film system described in US. Pat. No.3,615,427 issued Oct. 26, 1971. Processing of such film units, as wellas the specific composition of the processing composition, is detailedin the aforementioned patents and applications.

The specific composition or method of preparation of silver halideemulsions suitable for use in the present invention is not critical tothe operation of the present invention. For example, emulsions of thepresent invention may be employed in emulsions for wet processing,

emulsions employed in diffusion transfer processing and direct positiveemulsions. Conventional spectral and chemical sensitizers may beemployed as well as optional additives such as coating aids, hardeners,viscosity increasing agents, stabilizers, preservatives,'and the like.

Similarly, the photoresponsive material will preferably comprise acrystal of a silver compound, for example, one or more of the silverhalides such as silver chloride, silver iodide, silver bromide, or mixedsilver halides such as silver chlorobromide, silver chloroiodobromide,or silver iodobromide, of varying halide ratios and varying silverconcentrations.

What is claimed is:

l. A photosensitive silver halide emulsion having associated therewith astable, water-soluble compound of the formula:

AgL 2x wherein L is anon-aromatic macrocyclic ligand having" whereineach Y is a carbon chain of at least 2 carbon atoms and X is an anion.

' 2. A product as defined in claim 1 wherein said emul-65,

four electron donor atoms and is represented by the formula: c

' /Y\ :N l Y Y N: :N4 I

4. The product as defined in claim 1 wherein L is a tetraamine. I

5. The product as defined claim 4 wherein L is 6. The product as definedin claim 4 wherein L is:

H c CCH 7. The product as defined in claim 4, wherein L is:

H ill 15TH, H2C

8. The product as defined in claim 4 wherein L is:

9. The product as defined in claim 1 wherein X is N 10. The product asdefined in claim 1 wherein said silver halide emulsion is carried on asupport.

11. A photographic silver diffusion transfer film unit which comprisesphotosensitive silver halide, silver precipitating nuclei and associatedwith said silver halide, a stable, water-soluble compound of theformula:

A L 2xwherein L is a non-aromatic macrocyclic ligand having fourelectron donor atoms and is represented by the formula:

wherein each Y is a carbon chain of at least 2 carbon atoms and X is ananion.

12. A product as defined in claim 11 wherein said film unit includes acommon support carrying a layer comprising silver precipitating nucleiand a layer comprising silver halide crystals.

13. A product as defined in claim 12 wherein said film unit is apermanent laminate.

14. A product as defined in claim 12 wherein said common support istransparent.

15. A photographic silver diffusion transfer film unit as defined inclaim 14 which includes an additive color screen intermediate saidtransparent common support and next adjacent essential layer.

16. In a photosensitive element including at least one light-sensitivesilver halide layer wherein each of which has a dye image-providingmaterial associated therewith, the improvement which comprises includingin at least one of said silver halide layers a stable, watersolublecompound of the formula:

wherein L is a non-aromatic macrocyclic ligand having four electrondonor atoms and is represented by the formula:

//Y\\ I r N N Y Y N :N I Y,

wherein each Y is a carbon chain of at least 2 carbon atoms and X is ananion.

17. An element as defined in claim 16 which includes a red-sensitivegelatino silver halide emulsion having a cyan dye image-providingmaterial associated therewith; a green-sensitive gelatino silver halideemulsion having a magenta dye image-providing material associatedtherewith; and a blue-sensitive gelatino silver halide emulsion having ayellow dye image-providing material associated therewith.

18. An element as defined in claim 16 which includes a positivecomponent including at least a dyeable straturn.

19. A photographic film unit which comprises, in

combination:

a photosensitive element having a diffusion transfer image-receivingelement affixed at least one edge thereof, said photosensitive elementcomprising a support carrying:

a. a red-sensitive silver halide emulsion having associated therewith acyan dye developer;

b. a green-sensitive silver halide emulsion having associated therewitha magenta dye developer; c. a blue-sensitive silver halide emulsionhaving associated therewith a yellow dye developer; at least one of saidsilver halide emulsions having disposed therein a stable, water-solublecompound of the formula:

wherein L is a non-aromatic macrocyclic ligand having four electrondonor atoms and is represented by the formula:

wherein each Y is a carbon chain of at least 2 carbon atoms and X is ananion;

said diffusion transfer image-receiving element comprising a supportlayer carrying:

an alkaline processing composition permeable and dyeable layer whereinsaid photosensitive and said image-receiving elements are adapted to besuperposed, the support layers of each comprising the extremities of thesuperposed structure.

20. The product as defined in claim 19 wherein said compound is disposedin each of said silver halide emulsion layers.

21. The product as defined in claim 19 including a rupturable containerretaining an aqueous alkaline processing composition affixed one edge ofsaid photosensitive and said image-receiving elements and adapted uponrutprue to distribute its contents intermediate said superposedphotosensitive and said imagereceiving elements. a

22. The product as defined in claim 19 wherein said photographic filmunit comprises a composite structure comprising said photosensitiveelement and said imagereceiving element permanently affixed each to theother in superposed relationship, the support layers of each of saidelements comprising the extremities of said composite structure.

23. A photographic process which comprises developing an exposedphotosensitive element comprising an exposed silver halide emulsioncontaining a stable, water-soluble compound of the formula:

AgL 2X wherein L is a non-aromatic macrocyclic ligand having fourelectron donor atoms and is represented by the, formula:

wherein each Y is a carbon chain of at least 2 carbon atoms and)( is ananion.

24. A silver diffusion transfer photographic process which comprises, incombination, the steps of:

a. exposing a photographic film unit comprising photosensitive silverhalide and silver precipitating nuclei wherein said silver halide hasassociated therewith a stable, water-soluble compound of the formula:

AgL 2X- wherein L is a non-aromatic macrocyclic ligand having fourelectron donor atoms and is represented by the formula:

Y\ I N wherein each Y is a carbon chain of at least 2 carbon atoms and Xis an anion; and

b. contacting said exposed film unit with a processing compositioncontaining a silver halide developing agent and a silver halide solvent,thereby providing a visible diffusion transfer process silver image tosaid unit, as a function of the point-to-point degree of exposurethereof.

25. A diffusion transfer color photographic process as defined in claim24 wherein said film unit includes a color screen and exposure of saidfilm unit is accomplished by radiation transmitted through said screen.

26. A diffusion transfer multicolor photographic process as defined inclaim 25 wherein said color screen comprises a trichromatic additivecolor screen comprising red, green and blue optical filter elements in ascreen pattern.

27. A silver diffusion transfer photographic process as defined in claim25 which comprises, in combination, the steps of:

wherein L is a non-aromatic macrocyclic ligand having four electrondonor atoms and is represented by the wherein each Y is a carbon chainof at least 2 carbon atoms and X is an anion; and

b. contacting the exposed silver halide layer with an aqueous processingcomposition containing a silver halide developing agent and a silverhalide solvent thereby providing a visible silver image to said filmunit, in terms of the unexposed areas of said silver halide layer, asthe function of the point-to-point degree of exposure thereof.

. 28. A process for forming photographic images which comprises, incombination, the steps of:

a. exposing a photographic film unit which comprises a plurality oflayers including at least a first photosensitive silver halide layerhaving associated therewith diffusion transfer dye image-providingmaterial and a stable, water-soluble compound of the formula:

AgL 2X- wherein L is a non-aromatic macrocyclic ligand having fourelectron donor atoms and is represented by the formula:

wherein each Y is a carbon chain of at least 2 carbon atoms and X is ananion, and a diffusion transfer process image-receiving layer adapted toreceive solubilized image-forming material diffusing thereto;

b. contacting said photosensitive silver halide emulsion with an aqueousalkaline processing composition;

c. effecting thereby substantial development of said silver halideemulsion;

d. forming thereby an imagewise distribution of mobile image-formingmaterial as a function of the point-to-point degree of emulsionexposure; and e. transferring by diffusion at least a portion of saidimagewise distribution of mobile image-forming material to said layeradapted to receive said material to provide thereto an image in terms ofsaid imagewise distribution.

1. A PHOTOSENSITIVE SILVER HALIDE EMULSION HAVING ASSOCIATED THEREWITH ASTABLE, WATER-SOLUBLE COMPOUND OF THE FORMULA:
 2. A product as definedin claim 1 wherein said emulsion includes spectral sensitizing agents.3. A product as defined in claim 1 wherein said emulsion includeschemical sensitizing agents.
 4. The product as defined in claim 1wherein L is a tetraamine.
 5. The product as defined in claim 4 whereinL is
 6. The product as defined in claim 4 wherein L is:
 7. The productas defined in claim 4, wherein L is:
 8. The product as defined in claim4 wherein L is:
 9. The product as defined in claim 1 wherein X is NO3.10. The product as defined in claim 1 wherein said silver halideemulsion is carried on a support.
 11. A photographic silver diffusiontransfer film unit which comprises photosensitive silver halide, silverprecipitating nuclei and associated with said silver halide, a stable,water-soluble compound of the formula: AgL 2 2X wherein L is anon-aromatic macrocyclic ligand having four electron donor atoms and isrepresented by the formula:
 12. A product as defined in claim 11 whereinsaid film unit includes a common support carrying a layer comprisingsilver precipitating nuclei and a layer comprising silver halidecrystals.
 13. A product as defined in claim 12 wherein said film unit isa permanent laminate.
 14. A product as defined in claim 12 wherein saidcommon support is transparent.
 15. A photographic silver diffusiontransfer film unit as defined in claim 14 which includes An additivecolor screen intermediate said transparent common support and nextadjacent essential layer.
 16. In a photosensitive element including atleast one light-sensitive silver halide layer wherein each of which hasa dye image-providing material associated therewith, the improvementwhich comprises including in at least one of said silver halide layers astable, water-soluble compound of the formula: AgL 2 2X wherein L is anon-aromatic macrocyclic ligand having four electron donor atoms and isrepresented by the formula:
 17. An element as defined in claim 16 whichincludes a red-sensitive gelatino silver halide emulsion having a cyandye image-providing material associated therewith; a green-sensitivegelatino silver halide emulsion having a magenta dye image-providingmaterial associated therewith; and a blue-sensitive gelatino silverhalide emulsion having a yellow dye image-providing material associatedtherewith.
 18. An element as defined in claim 16 which includes apositive component including at least a dyeable stratum.
 19. Aphotographic film unit which comprises, in combination: a photosensitiveelement having a diffusion transfer image-receiving element affixed atleast one edge thereof, said photosensitive element comprising a supportcarrying: a. a red-sensitive silver halide emulsion having associatedtherewith a cyan dye developer; b. a green-sensitive silver halideemulsion having associated therewith a magenta dye developer; c. ablue-sensitive silver halide emulsion having associated therewith ayellow dye developer; at least one of said silver halide emulsionshaving disposed therein a stable, water-soluble compound of the formula:AgL 2 2X wherein L is a non-aromatic macrocyclic ligand having fourelectron donor atoms and is represented by the formula:
 20. The productas defined in claim 19 wherein said compound is disposed in each of saidsilver halide emulsion layers.
 21. The product as defined in claim 19including a rupturable container retaining an aqueous alkalineprocessing composition affixed one edge of said photosensitive and saidimage-receiving elements and adapted upon rutprue to distribute itscontents intermediate said superposed photosensitive and saidimage-receiving elements.
 22. The product as defined in claim 19 whereinsaid photographic film unit comprises a composite structure comprisingsaid photosensitive element and said image-receiving element permanentlyaffixed each to the other in superposed relationship, the support layersof each of said elements comprising the extremities of said compositestructure.
 23. A photographic process which comprises developing anexposed photosensitive element comprising an exposed silver halideemulsion containing a stable, water-soluble compound of the formula: AgL2 2X wherein L is a non-aromatic macrocyclic ligand having four electrondonor atoms and is represented by the formula:
 24. A silver diffusiontransfer photographic process which comprises, in combination, the stepsof: a. exposing a photographic film unit comprising photosensitivesilver halide and silver precipitating nuclei wherein said silver halidehas associated therewith a stable, water-soluble compound of theformula: AgL 2 2X wherein L is a non-aromatic macrocyclic ligand havingfour electron donor atoms and is represented by the formula:
 25. Adiffusion transfer color photographic process as defined in claim 24wherein said film unit includes a color screen and exposure of said filmunit is accomplished by radiation transmitted through said screen.
 26. Adiffusion transfer multicolor photographic process as defined in claim25 wherein said color screen comprises a trichromatic additive colorscreen comprising red, green and blue optical filter elements in ascreen pattern.
 27. A silver diffusion transfer photographic process asdefined in claim 25 which comprises, in combination, the steps of: a.exposing a film unit which comprises a permanent laminate which includesa support carrying on one surface a layer comprising silverprecipitating nuclei and a layer comprising photosensitive silver halidehaving associated therewith a stable, water-soluble compound of theformula: AgL 2 2X wherein L is a non-aromatic macrocyclic ligand havingfour electron donor atoms and is represented by the formula:
 28. Aprocess for forming photographic images which comprises, in combination,the steps of: a. exposing a photographic film unit which comprises aplurality of layers including at least a first photosensitive silverhalide layer having associated therewith diffusion transfer dyeimage-providing material and a stable, water-soluble compound of theformula: AgL 2 2X wherein L is a non-aromatic macrocyclic ligand havingfour electron donor atoms and is represented by the formula: